The present invention is directed to a mounting device for securing a fuel injector.
A mounting device for mounting a fuel injector on an intake manifold, which axially attaches the fuel injector to the fuel distribution line or to a plug nipple by using a mounting element which is designed as a U-shaped clamp having two legs which are elastic in the radial direction, is described in German Published Patent Application No. 29 26 490. In the assembled state, the clamp reaches through corresponding recesses of the plug nipple and is snappable into a recess in a connection fitting of the fuel injector, the recess being designed as a ring groove. The axial clearance between the recesses and the clamp as well as between the ring groove and the clamp should be kept small, in order to achieve accurate fixation of the fuel injector without stressing the gasket.
The stressing effect of the different mounting parts on the fuel injector is a particular disadvantage of the mounted device described in German Published Patent Application No. 29 26 490. The power flow generated in the fuel injector results in deformations and thus to changes in the lift of the valve needle including jamming, as well as in a compression and bending strain of the housing parts, which are generally thin-walled and welded together at several points. In addition, any fixation measure, e.g., the use of a bearing collar, results in an enlargement of the radial dimension of the fuel injector and thus in an increase in required space for mounting.
In accordance with the mounting device for a fuel injector according to the present invention, the fuel injector has a collar or shoulder which is mounted on a spray-discharge-side end at which an elastic hold-down device engages, which completely or partially surrounds the end of the fuel injector, whereby the fuel injector is held down in the cylinder head. Thus, axial or bending forces may act only on the valve housing at the downstream end.
The hold-down devices may be easily manufactured by, for example, stamping them out of sheet metal, and they may be suitable for individual fuel injectors, as well as for in-line arrangements of fuel injectors.
The hold-down devices may be fixed in a simple manner to the front face of the cylinder head by using screws or clamping claws.
The hold-down device may be designed as a hold-down pot, which may add greater stability to the fuel injector in the receiving bore of the cylinder head.
The slots and elastic clips formed at the end of the hold-down pot may allow a quick and simple assembly and disassembly of the fuel injector.
Due to shoulders in the hold-down pot, the mounting device is installable in almost any receiving bore of a cylinder head, and may thus be used as an adapter when the bore cross-section is excessively large.
Exemplary embodiments of the present invention are schematically illustrated in the drawings and are explained in greater detail in the following description.